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931.
932.
Bibhu P. Swain Bhabani S. Swain Seung M. Yang Nong M. Hwang 《Applied Surface Science》2009,255(11):6033-6037
Nanocrystalline silicon (nc-Si) films were deposited by hot wire chemical vapor deposition with applying positive or negative filament biases. These films were characterized by Raman spectroscopy, field emission scanning electron microscopy and X-ray photoelectron spectroscopy. Plasmon loss of the Si(2p) band region was shifted to higher energy due to dielectric changes with applied filament biases from negative to positive voltage. A semi-quantitative study of the valence band structure was employed to analyze the bias effect of the valance band in nc-Si networks. Nc-Si with a positive filament bias shows better microstructural properties than those with a negative bias and without biasing nc-Si films. 相似文献
933.
Jung Seop Lim Isao Noda Seung Soon Im 《Journal of Polymer Science.Polymer Physics》2006,44(19):2852-2863
Poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHB‐HHx) and methoxy poly(ethylene glycol) (MPEG) blends were prepared using melt blending. The single glass transition temperature, Tg, between the Tgs of the two components and the negative χ value indicated that PHB‐HHx and MPEG formed miscible blends over the range of compositions studied. The Gordon–Taylor equation proved that there was an interaction between PHB‐HHx and MPEG in their blends. FTIR supported the presence of hydrogen bonding between the hydroxyl group of MPEG and the carbonyl group of PHB‐HHx. The spherulitic morphology and isothermal crystallization behavior of the miscible PHB‐HHx/MPEG blends were investigated at two crystallization temperatures (70 and 40 °C). At 70 °C, melting MPEG acted as a noncrystalline diluent that reduced the crystallization rate of the blends, while insoluble MPEG particles acted as a nucleating agent at 40 °C, enhancing the crystallization rate of the blends. However, no interspherulitic phase separation was observed at the two crystallization temperatures. The constant value of the Avrami exponent demonstrated that MPEG did not affect the three‐dimensional spherulitic growth mechanism of PHB‐HHx crystals in the blends, although the MPEG phase, such as the melting state or insoluble state, influenced the crystallization rate of the blends. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2852–2863, 2006 相似文献
934.
Chang Gi Cho Yu Seung Kim Xiang Yu Melinda Hill James E. McGrath 《Journal of polymer science. Part A, Polymer chemistry》2006,44(20):6007-6014
A sulfonimide‐containing comonomer derived from 4,4′‐dichlorodiphenylsulfone was synthesized and copolymerized with 4,4′‐dichlorodiphenylsulfone and 4,4′‐biphenol to prepare sulfonimide‐containing poly(arylene ether sulfone) random copolymers (BPSIs). These copolymers showed slightly higher water uptake than disulfonated poly(arylene ether sulfone) copolymer (BPSH) controls, but their proton‐conductivity values were very comparable to those of the BPSH series with similar ion contents. The proton conductivity increased with the temperature for both systems. For samples with 30 mol % ionic groups, BPSI showed less temperature dependence in proton conductivity and slightly higher methanol permeability in comparison with BPSH. The thermal characterization of the sulfonimide copolymers showed that both the acid and salt forms were stable up to 250 °C under a nitrogen atmosphere. The results suggested that the presumed enhanced stability of the sulfonimide systems did not translate into higher protonic conductivity in liquid water. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6007–6014, 2006 相似文献
935.
Jin‐Woong Kim Jung‐Eun Lee Jee‐Hyun Ryu Jong‐Suk Lee Su‐Jin Kim Sang‐Hoon Han Ih‐Seop Chang Hak‐Hee Kang Kyung‐Do Suh 《Journal of polymer science. Part A, Polymer chemistry》2004,42(10):2551-2557
A new colloidal silver system is presented in which a fine colloidal silver is in situ deposited onto functionalized porous poly(ethylene glycol dimethacrylate) [poly(EGDMA)] microspheres. The effectiveness of the silver deposition has been investigated through an examination of the surface characteristics of poly(EGDMA) microspheres. The result reported in this study demonstrate that the control of the surface area and surface functionality (in this study, a hydroxyl group) of poly(EGDMA) microspheres is an important factor that practically determines the degree of deposition of colloidal silver. X‐ray analysis has shown that silver nanoparticles are dispersed evenly on inner and outer surfaces and have a face center cubic phase. Preservation testing has shown that silver‐containing poly(EGDMA) microspheres have powerful antibacterial properties and, therefore, have significant potential as new preservatives. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2551–2557, 2004 相似文献
936.
Sung‐Chul Kim Seung‐Min Park Jin Soo Park Seung‐Joon Lee Sung‐Ho Jin Yeong‐Soon Gal Jae Wook Lee 《Journal of polymer science. Part A, Polymer chemistry》2008,46(3):1098-1110
Two PPV‐based bipolar polymers containing 1,3,4‐oxadiazole pendant groups were synthesized via the Gilch polymerization reaction for use in light‐emitting diodes (LEDs). The resulting polymers were characterized using 1H and 13C NMR, elemental analysis, DSC, and TGA. These polymers were found to be soluble in common organic solvents and are easily spin‐coated onto glass substrates, producing high optical quality thin films without defects. The electro‐optical properties of ITO/PEDOT/polymer/Al devices based on these polymers were investigated using UV‐visible, PL, and EL spectroscopy. The turn‐on voltages of the OC1Oxa‐PPV and OC10Oxa‐PPV devices were found to be 8.0 V. The maximum brightness and luminescence efficiency of the OC1Oxa‐PPV device were found to be 544 cd/m2 at 19 V and 0.15 cd/A, respectively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1098–1110, 2008 相似文献
937.
938.
We introduce a generalized Wiener measure associated with a Gaussian Markov process and define a generalized analytic operator-valued
function space integral as a bounded linear operator from L
p
into L
p^\prime
(1<p ≤ 2) by the analytic continuation of the generalized Wiener integral. We prove the existence of the integral for certain functionals
which involve some Borel measures. Also we show that the generalized analytic operator-valued function space integral satisfies
an integral equation related to the generalized Schr?dinger equation. The resulting theorems extend the theory of operator-valued
function space integrals substantially and previous theorems about these integrals are generalized by our results. 相似文献
939.
Byung-Gook Park Dae Hwan Kim Kyung Rok Kim Ki-Whan Song Jong Duk Lee 《Superlattices and Microstructures》2003,34(3-6):231
We have implemented a sidewall spacer patterning method for novel dual-gate single-electron transistor (DGSET) and metal–oxide–semiconductor-based SET (MOSET) based on the uniform SOI wire, using conventional lithography and processing technology. A 30 nm wide silicon quantum wire is defined by a sidewall spacer patterning method, and depletion gates for two tunnel junctions of the DGSET are formed by the doped polycrystalline silicon sidewall. The fabricated DGSET and MOSET show clear single-electron tunneling phenomena at liquid nitrogen temperature and insensitivity of the Coulomb oscillation period to gate bias conditions. On the basis of the phase control capability of the sidewall depletion gates, we have proposed a complementary self-biasing method, which enables the SET/CMOS hybrid multi-valued logic (MVL) to operate perfectly well at high temperature, where the peak-to-valley current ratio of Coulomb oscillation severely decreases. The suggested scheme is evaluated by SPICE simulation with an analytical DGSET model, and it is confirmed that even DGSETs with a large Si island can be utilized efficiently in the multi-valued logic. 相似文献
940.
Ryu Sasaki 《Zeitschrift fur Physik C Particles and Fields》1984,24(2):163-170
We study the classical solutions of the complex Grassmannian nonlinear sigma models and of theCP N?1 model in two euclidean dimensions. Exact solutions of various types, which seem to be complete, are constructed explicitly in an elementary way, namely in terms of holomorphic functions and the Gramm-Schmidt orthonormalization procedure. A new type of discrete symmetry transformations which map one solution into another is presented. 相似文献